Antimicrobial susceptibility testing and identification of exoS and exoU toxin genes of Pseudomonas aeruginosa isolated from clinical samples in lebanon. (c2008)

Abstract

Pseudomonas aeruginosa is a major cause of nosocomial infections. It can secrete toxins directly into the eukaryotic host through the type III secretion system. ExoS and ExoU are two major exotoxins that contribute to the virulence and pathogenecity of P. aeruginosa. The emergence of antibiotic resistance strains is increasing due to the high consumption of antimicrobial agents. PCR assays were used in this study to determine the distribution of exoS and exoU toxin genes among 100 P. aeruginosa clinical samples. Additionally, E-test was used to determine the antibiotic resistant profiles using five different antibiotics ciprofloxacin (CI), tobramycin (TM), ceftriaxone (TX), gentamycin (Gm), amikacin (Ak) that represent different classes of antimicrobial agents including aminoglycosides, flouroqiunolones, and third generation cephalosporins. The most effective antimicrobial agent was amikacin with 91 % of the isolates being susceptible while the least effective drug was ceftriaxone with 45% of samples being susceptible. Multiple drug resistance with P. aeruginosa was rarely detected with 4% of the isolates exhibiting resistance to all of the five tested antibiotics, 8% of the sampled showed multiple drug resistance to 3 and 4 drugs.